function che(){
  let check1 = document.getElementsByName("check1");
  // console.log(check1[0].checked);
  let check = document.getElementsByName("check");
  if(check1[0].checked==true){
    for(let i=0;i<check.length;i++){
      check[i].checked = true;
    }
  }else{
    for(let i=0;i<check.length;i++){
      check[i].checked = false;
    }
  }
}